I just stumbled across this today.
ATI has Demo software for their high-end graphics cards named Ruby.

http://www.ati.com/ruby/index.html

This Demo game isn't cheap though, 49.99 USD.

http://shop.ati.com/product.asp?sku=2599091

standard disclaimer:
 I am not associated with ATI in any way, (I don't even own any of their 
products).

-- 
David